Piano-key-repair clamp



E. R. CRANDALL.

PIANO KEY REPAIR CLAMP.

APPLICATION FILED JULY 1?, 1920.

1 71,073,- Patented Mar 8, 1921.

' W! 7 I /4 2/ A5 Z2 Z5 m m W WITNESSES V lNl/E/VTOR ER, 07% ndaZZ,

W wzwfi ATTORNEYS, I

UNITED STATES PATENT OFFICE.

PIANO-KEY-REPAIR CLAMP.

Specification of Letters Patent.

Patented Mains, 1921.

Application filed July 17, 1920. Serial No. 396,994.

vide a tool of the above character in the form of a clamp for holding the ivory veneer to the key while the glue is setting, the clamp being designed for and permitting the head piece and front piece to be clamped in position at the same time, and without removing the key, as is necessary in accordance with the manner of repairing as now practised.

A further object of the invention is to provide an improved clamp having novel means for accommodating the metal guide post or pin carried by the post support and adapted to engage a guide-pin hole or opening customarily formed in the bottom of the piano key, thus permitting the repairing operation or attachment of the ivories to the key without removing the latter and thereby saving much time and labor, since it only necessitates that the lock strip or narrow board in front of the keys be removed in order to apply the clamps, any number of which may be used at one time, owing to the fact that the same are the same width as the key.

With the above objects in View, the invention consists in certain novel features of construction and combination of parts, as will be hereinafter fully described and pointed out in the claims.

In the accompanying drawings:

Figure 1 is a sectional side elevation showing the improved clamp in applied position,

Fig. 2 is an end elevation of the clamping body,

Fig. 3 is a horizontal sectional view taken on the line 33 of Fig. 1, to show the lower clamping jaw detached,

Fig. 4c is a plan view of the top clamp plate, and

Fig. 5 is a similar view of the end clamp plate.

Referring to the drawings in detail, the

numeral 10 designates the usual post support of a piano, the same running longitudinally in rear of the ordinary lock strip or narrow board in front of the keys, which is secured in position by four screws generally from the bottom, the removal of the lock strip or narrow board permitting the keys 11 to be exposed at their outer ends. The post support 10 is arranged with a series of metal guide posts or pins 12 extending in an upright position and engaging or being received within the guide-pin hole or openings 13 customarily formed in the bottom of the piano keys.

In order to apply the ivories or ivory veneers, the tail piece 14 is secured in position, and the present invention is designed for securing the head piece 15 and the front piece 16 in position at the same time, and without removing the key. Of course, it is to be understood that the head piece and front piece are particularly subject to use and wear, thereby coming loose almost to the exclusion of the tail piece. The clamp includes a U-shaped body 17 preferably of substantially 'T-shaped cross section, that is, formed of a flat body having a reinforcing rib or web'l8 formed at its top portion with a rearwardly internally threaded sleeve 19 receiving a clamping screw 20 therein. A top clamp plate 21 is disposed to engage the head piece 15, and is provided with an open pocket extension 22 receiving the rounded tapered end of the screw shank for relative angular movement therein, while the front end of the plate is provided with a depending flange 23 designed to engage the outer end of the headpiece which is disposed against the upper end or edge of the front piece 16.

In order that the device may be so applied, the lower jaw is provided with a longitudinal slot 24: extending in from the free end thereof and into the reinforcing rib or web, which straddles the same at the bifurcation or slot, said reinforcing portions being indicated at 25 and engaging upon opposite sides of the metal guide post or pin 12, so that the device may be applied to the key or any number of the same successively across the keyboard, without removing the keys. This is due to the fact that the clamp is of the same width as the key and thus, it is only necessary to remove the ordinary lock strip or narrow board in front of the keys, by taking out four screws from the bottom, in order to secure the clamp in position, thus facilitating the repairing or covering operation, re-gluing of ivories or the like, and saving much time and labor. The active face of the lower jaw is preferably serrated as indicated at 26, in order to prevent slipping, thus insuring that the veneers will be properly secured in position and set when glued and clamped as described. a 7

As before mentioned, "the clamp plate flange 23 holds the head piece against the tail piece at the outer end or edge of the latter, and against the top end or edge of the front piece 16. However, in order to secure the latter against the front end of the key, the bight portion of the clamp body is provided with a downwardly and forwar'dly inclined internally threaded sleeve 27 receiving a clamping screw 28 similar to the screw 20, each being of the thumb screw type, in order to facilitate the operation thereof without the use of tools. A front clamp plate 29 is disposed to engage the front piece 16 and is provided with an open socket 30 corresponding to the socket 22, it being in the form of a projection permitting free angular movements of the plate with respect to the screw, in order that the plate will remain squarely against the front end of the key.

Thus, it will appear that the upper clamping screw will hold the head piece against the tail piece, and also a ainst the upper edge of the front piece, w ile the forward clamping screw at the lower portion of the clamp, will hold the front piece against the bottom face of the head piece, thus securely holding the ivory veneer to the key and in contact while the glue is setting, simultaneously securing the front and head pieces in position as well as forcing the head piece against the tail ivory, so as to prevent the glue from entering between them, while securely connecting the glued portions. An im ortant feature of the device, is the provision of the bifurcated or slotted lower jaw of the clamp body or frame, the slot or opening in the body of the clamp allowing it to pass behind the metal guide post or pin which is ordinarily about t of an inch from the front end of the white piano key. This will save much time and labor, as it will obviate the necessity of removing the key and in addition, will serve to facilitate and correctly apply the ivory veneer pieces, in a manner which could ordinarily be done only by removing the keys from the piano. Also, by reason of the fact that the clamps are the same width as the keys, any number of the same may be applied after removing the lock strip or narrow board in front of the keys, which can be very conveniently done by taking out the four screws at the bottom, the clamps being applied at the front ends of the keys and pressed in position, so that the metal guide posts or pins will be received within the openings or slots of the clamps.

In use, the lock strip or narrow board is removed and then the clamp applied to the front end of the key with the slot or opening engaged by the guide post. The plate 21 is then applied and the screw 20 tightened down 011 the plate, the veneers or covering pieces having been previously applied and glued. Then the plate 29 is applied and the screw 28 tightened down on the same. In about four hours, the pieces will be thoroughly set, and the clamps can be removed leaving the keys in proper condition and without the necessity of employing tools. It is also an advantage'that two or more adjacent keys can be repaired at the same time, the repairing operation of each key being independent.

In view of the foregoing, it is thought that th operation of the device will be readily understood and in view of the sim plicity and practical value that it will commend itself to those skilled in the art.

Having thus described my invention, what I claim is l. A clamp of the class described, comprising a U-shaped clamp body having a slotted portion, said slot being relatively narrow and extending a short distance from the free end thereof, said slot being adapted to engage the guide post of a key and post support thereof, a clamping plate for disposition between the upper jaw of the body and the key, an inclined clamping screw engaged through the upper jaw and the plate, a plate adapted to be disposed between the bight portion of the clamp and the front end of the key, and an inclined clamping screw engaged through said bight portion and with the plate.

2. A clamp of the class described, comprising a U-shaped body having a rearwardly inclined threaded socket or sleeve at the upper jaw thereof, a clamping screw engaged through said sleeve, a downwardly and forwardly inclined sleeve provided at the lower portion of the bight portion of the clamp body, a clampingscrew engaged therethrough, a plate having an extension socket for engagement with the first named screw and a clamping plate having a similar socket for engagement with the second named screw.

3. A clamp of the class described, comprising a U-shaped bo'dy'having a rearwardly inclined threaded socket or sleeve at the upper jaw thereof, a clamping screw engaged through said sleeve, a downwardly and forwardly inclined sleeve provided at the lower portion of the bight portion of the clamp body, a clamping screw engaged therethrough, a plate having an extension socket for engagement with the first named screw and a clamping plate having a similar socket for engagement with the second named screw, said clamp body having its lower end bifurcated to form an opening receiving said pin therein, and permitting application of the clamp to a key while the latter is in position.

4:. A clamp of the class described comprising a Ushaped body having a slotted lower jaw adapted to engage the bottom portion of a key between the post support and key, said post support having a guide post engaging an opening in the key through said slot in the jaw, said lower jaw being serrated, a downwardly and rearwardly acting jaw clamp at the top jaw of the body for engaging the head piece of the key veneer to force the same downwardly and against the tail piece of the veneer, and an upwardly and rearwardly acting clamp carried by the lower bight portion of the body to force the front piece of the key veneer upwardly and in contact with the front end of the key.

5. In a piano key repair clamp, adapted for use with piano keys having a guide pin hole and a post support having a pin engaging said hole, a clamp body to engage above and below the key and at the forward end thereof, said bod having a flat serrated lower jaw provide with means to accommodate said pin and permit displacement of the lower portion thereof beyond the pin, and clamping means carried by the body to hold the head and front pieces in position when glued for settin EDWARD ROBERT ORKNDALL. 

